The present invention relates to a scanning device for scanning an image carrier, comprising a linear array of scanning elements, a holder for the array, which extends in the longitudinal direction of the array, and positioning means to maintain the scanning elements at a predetermined position from the image carrier. A scanning device of this kind is known from European Patent 0 401 316, which describes a scanning device for forming an image on a photoconductive image carrier by means of a linear array of co-operating LEDs and lenses. In this device the lens array focuses the light emitted by the array of LEDs into the plane in which the image carrier moves. In order to keep the linear array in the required position with respect to the imaging plane occupied by the image carrier, the arrays of LEDs and lenses in this known scanning device are fixed on a holder made from relatively thick metal and provided with stiffening ribs in order to keep the linear array in a predetermined focusing position throughout with respect to the image carrier.
Since in order to form an uninterrupted image the linear array holder can bear against the image carrier only outside its operative zone, the array is sensitive to sagging or deflection, and particularly in the case of a long linear array in large-format scanning devices in which the linear array is disposed beneath or above the imaging plane. This manifests itself in the form of locally non-sharp imaging.